James oag and john mcdonald



(No Model.) l

J. OAG J. MODONALD. DRIVING GEAR FOR BIGYGLES.

No. 578,260. Patented Mar. 2, 1897.

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PV L'/CQSSQ@ VW @RM1/A2M@ UNITED STATES l PATENT OFFICE.

JAMES OAG AND JOHN MCDONALD, OF TORONTO, CANADA.

DRIVING-G EAR FOR BICYCLES.

SPECIFICATION forming part of Letters Patent No. 578,260, dated March 2,1897'. Application filed May 8,1896.` Serial No. 590,742. (No model.)

/o LZZ whom, it may concern;

Be it known that we, JAMES OAG, blacksmith, and JOHN MCDONALD,machinist, of the city of Toronto, in the county of York and Province ofOntario, Canada, haver'invented a certain new and Improved Driving-,Gearfor Bicycles, of which the following is a specification.

The object `of our invention is to devise a crank-and-lever driving-gearfor bicyclists in which the possibility of sticking on a deadcenter isobviated; and it consists, essentially, of a bent lever pivoted on theframe, its long arm havin g a pedal connected thereto and its short armconnected by a pitman to 'a crank on the axle of the ordinary drivingsprocket-wheel of the bicycle, a buffer being so connected to the longarm of the lever as to come into contact with the pitman when the crankis on a dead-center and so throw it over the center, substantially ashereinafter more particularly described and then definitely claimed.

Figure l is a side view of a bicycle provided with our improveddriving-gear. Fig. 2 is an enlarged detail and side elevation of thedriving-gear, showing the crank passing over the dead-center. Fig. 3 isa detail in elevation of the spring-buffer.

In the drawings like letters of reference indicate corresponding partsin the different figures.

A is a bent lever pivoted at-ct to the frame 0f the bicycle. To the longarm .B of this lever is connected the pedal l).

O is the short arm of the lever, to which is pivoted one end of thepitman D, the other end of the said pitman being journaled on the crankE, which is fast on the axle of the ordinary driving sprocket-wheel F ofthe bicycle. This sprocket-Wheel is geared in the ordinary manner to therear wheel 0f the bicycle, as indicated.

Although we speak of a separate crank-arm being provided on the axle ofthe sprocketwheel F, yet a wrist-pin 'on one of the spokes of thesprocket-wheel would answer the purpose of ourinvention, the separatecrank-arm being only necessary on the other side of the frame, where ofcourse all the driving parts are duplicated.

G is a bolt adapted to slide through the lug As shown in Fig. 2, whenthe cranks E are on the dead-center the end of the bolt G comes incontact with the pitman D and thus applies a yielding pressure to it tothrow the crank over the dead-center. Of course if the position of thebolts G were very accurately determined it might be possible to dispensewith the coil-spring I; but in practice it is found preferable to usethe spring, as jarring of any kind is thus obviated. We consider thisbuffer a most important feature of our invention, as in practice it isfound, especially when starting, that there is great danger of thecranks striking on the dead-center and of the rider, by pressure on thepedals, bending or otherwise damaging'the frame of the bicycle. When thebuffers are used, however, the down lever just nicely starts the cranksoff the dead-center, and the rider is enabled to tell by the feel of themechanism when it is safe to apply all his power on the downstroke ofthe other lever. n

As it is desirable to change the gear of the bicycle to suit differentriders or to suit different conditions of roads under which the' bicycleis to be ridden, we provide the short arm c of the bent lever a with aseries of holes, in any one of which the pitman D may be pivoted.

From the above description it will be seen that we have invented a verysimple and effective up-and-down driving-gear for bicycles in which notoothed wheels or ratchets are used and in which no springs are requiredto return the levers to their raised position after a stroke of thefoot. It Will'also be seen that we have invented a very effectivelmethod of preventing all danger of the gear striking on the dead-centerand thus rendering the bicycle liable to injury.

It should be mentioned that the nature of the spring-bulfer isimmaterial, as a rubber block, a flat sprin g, or any other form of IOOspring might be used instead of the springbolt shown.

What We claim as our invention is- In a bicycle, the combination withthe bent lever A, pivoted to the frame of the bieyele; the pedal bconnected to the long arm B of the bent lever; the crank E connectedwith the axle of the driving sprocket-Wheel F of the ordinary gearing;and the pitnian D connecting the said crank With the short arm C of thebent lever and situated under said bent lever; of a builer connectedwith the long arm of said bent lever and constructed and arranged tocome into Contact with the pitlnztn D and throw the Crank over the deadI5 center when the said bent lever approaches the said pitlnztn,substantially as and for the purpose specified.

Toronto, April 30, 1896.

JAMES OAG. JOHN MCDONALD. In presence of J. EDW. MAYBEE, A. M. NEFF.

